RC2 release candidate for 4/15

Merge pull request #188 from DustinCampbell/update-omnisharp

Update with latest OmniSharp and pick correct version for current Linux distribution

RC2 release candidate for 4/8

Merge pull request #163 from gregg-miskelly/UpdateCoreCLRVer

Update CoreCLR to rc2-24008

Initial RC2 release

Merge pull request #153 from DustinCampbell/fix-case-sensitivity

Don't search for OmniSharp launcher case-insensitively

Support latest .NET CLI

Merge pull request #139 from DustinCampbell/update-omnisharp

Update to support new OmniSharp release